Collapsible form for concrete culverts.



W. BURGNER. GOLLAPSIBLE FORM FOR CONCRETE GULVERTS. APPLIOATION FILEDSEPT. 28,1911.

1,-()2"7,17( 5. Patented May 21,1912.

= ATTORNEYS I COLUMBIA PLANOGRAPH 60.,WASHINGTON, D. c.

WILLIAM BURGNER, F CART'HAGE, ILLINOIS.

COLLAPSIBLE FORM. FOR CONCRETE GULVERTS.

Specification of Letters Patent.

Application filed September28, 1911. Serial No. 651,739.

To all whom it may concern:

Be it known that I, WILLIAM BURGNER, a

u citizen of the United. States, and a resident of Carthage, in thecounty of Hancock and State of Illinois, have invented a new andImproved Collapsible Form for Concrete Culverts, of which the followingis a full, clear, and exact description.

The object of the invention is to provide a new and improved collapsibleform for concrete culverts, which is simple and durable in construction,cheap to manufacture, readily set up without requiring skilled labor,and conveniently collapsed to allow removal of the parts from the endsof the culvert after the concrete has set.

For the purpose mentioned use is made of a skeleton frame formed of sidebars, transverse arch ribs, each made in sections, secured to the saidside bars, and having their free ends overlapping, and a top barextending underneath the arch ribs and providedwith longitudinal pinsadapted to engage registering apertures; in the said rib sections. I

A practical embodiment of the invention is represented in theaccompanying drawings forming a part of this specification, in whichsimilar characters of reference indicate corresponding parts in all theviews.

Figure 1 is a plan view of the skeleton frame of the collapsible formfor concrete culverts; Fig. 2 is an enlarged end elevation of the same;Fig. 3 is an enlarged longitudinal section of the same on the line 3-3of Fig. 2; and Fig. 4 is an end elevation of part of the skeleton frameshowing the use of a splice platefor arch ribs.

The skeleton frame for the collapsible form' for concrete culvertsconsists essentially of spaced side bars A and B, preferably made of gaspipe or the like, and connected with each other by spacedarch ribs C,each formed of two segmental sections C, C secured at their lower endsto the tops of the side bars A and B and having I their upper free endsoverlapping and provided with sets of apertures C C adapted. .toregister with each other for engagement by a longitudinal pin D securedto the top of a top bar E extending underneath the ribs C and parallelto the side bars A and B.

By reference to the drawings, it will be noticed that the pins D extendin one direction so as to readily engage the corresponding sets ofregistering apertures C or C 7 each section having an end aperture C andan intermediate aperture C*, it being understood that for narrow archesthe pins D engage the sets of apertures C*, while for wider arches thepins D engage the registering apertures C For very wide arches use ismade of a splice bar F secured'by bolts Gto one of the sections C or Cand overlapping the other section C or C, and the said splice bar F isprovided at its free end with an aperture F adapted to register with acorresponding aperture in the overlapped section for engagement by a pinD of thetop bar E.-

In using the collapsible form, the side bars A and B are placed on thebottom of the section, and then the sections C, C are Patented May 21,1912.

engaged by the pins D of the top bar E, 7

after which the covering H is placed lengthwise on the arches C, asplainly indicated in Fig. 2, the covering H being of any approvedconstruction, preferably narrow matched boards or sheet metal plates orthe like. The concrete for forming the arch section is now placed inposition on the covering H, and after the concrete has set the operatorpulls the top bar E lengthwise from one end of the section so as todisengage the pins D from the corresponding regist'ering apertures ofthe rib sections C, C or the rib sections and splice plate F. The sidebars A and B will. now readily turn so as to swing the rib sections Cand C downward, as indicated in Fig. 2, to collapse the form and with itthe covering H to allow convenient removal of the collapsible parts fromthe section.

The skeleton frame shown and described is very simple and durable inconstruction, and composed of comparatively few parts which can bereadily connected with each other without requiring skilled labor, andwhich parts'can be quickly collapsed after the section is finished andthe concrete has sufiiciently set and hardened to allow removal of theform. For very long concrete sections two or more skeleton frames may beused, placed end to end.

By the use of'the top bar E and the locking pins D it will be noticedthat no further means are required for holding the parts of the skeletonframe in place, but, if desired, stay pieces of wood may be placedbetween the side bars A and B, but such stay pieces need not be attachedand will be of no use after the first filling of concrete is tampedalong each side, and they will probably loosen as the concrete is filledin over the crown, and in case of a storm will readily float out thusoffering no obstruction either to flood water or the collapsing andremoval of the form. I

It is understood that by the use of the collapsible form described, thesame can be completely collapsed and removed from the outside, thus notrequiring a person to crawl into the section over and under variouscross and diagonal stays, which have to be unbolted or unhooked beforethe form can be collapsed, as heretofore practised.

The collapsible form described does not require side supports and istherefore well adapted for use in places where a shallow stream crossesa roadway, while at the same time it may be used to arch over a deeperculvert where sides can be formed up in the usual way to any depthdesired. If the section thus built with extended sides is too shallowfor a person to enter, then the side forms put up in the usual way maybe taken down before the top or arch form is put in place, and in thiscase short posts of suitable size can be placed so as to support theside bars A and B at the proper height. When the section is done, thewhole can be collapsed and removed from the ends of the culvert.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. A skeleton frame constituting a collapsible frame for concreteculverts and comprising side bars, a plurality of arched ribs,

each of said ribs being made in sections secured at their outer ends tothe side bars and having their inner ends free to overlap one another,the said inner free ends being provided with registering apertures,locking pins adaptable for engagement through the registering aperturesin order to lock the ribs, and a member carrying said locking pins inorder that they may be simultaneously withdrawn, said member extendingbeneath the overlapped ends of the rib sections and receiving said endsdirectly thereon whereby to form a supplemental support for the same.

.2. A skeleton frame constituting a collapsible frame for concreteculverts and comprising side bars, a plurality of arch ribs, each ofsaid ribs being made in sections secured at their outer ends to the sidebars and having their inner ends free to overlap-one another, the saidinner free ends being provided with registering apertures, a top barextending beneath the overlapping ends of the plurality of ribs, andpins attached to the said top bar and adapted to simultaneously engagethe registering apertures of the ribs, said pins being so spaced fromsaid bar that the latter receives thereagainst, and forms a support for,the said ribs.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

WILLIAM BURGNER.

WVitnesses: WM. B. Rrssn, GEO. W. PAYNE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

